Separation

Centrifuges can be used to separate the cream from the skim milk. The centrifuge consists of up to 120 discs stacked together at a 45 to 60 degree angle and separated by a 0.4 to 2.0 mm gap or separation channel. Milk is introduced towards the inner edge of the disc stack. The stack of discs has vertically aligned distribution holes into which the milk is introduced.

Under the influence of centrifugal force the fat globules, which are less dense than the skim milk, move inwards through the separation channels toward the axis of rotation. Some skim is needed to carry the fat globules out of the separation, and the combination of fat globules in a much-reduced volume of skim milk is called "cream", i.e., creamis skim milk enriched in fat globules. The skim milk, now devoid of fat globules, will move outwards and leaves through a separate outlet.

A centrifuge